Altered Task-Evoked Corticolimbic Responsivity in Generalized Anxiety Disorder

Area of Science:

• Neuroscience
• Psychiatry

Background:

• Generalized anxiety disorder (GAD) is characterized by excessive worry and heightened responses to uncertainty.
• Functional neuroimaging techniques are increasingly used to investigate the neural underpinnings of GAD.

Purpose of the Study:

• To review and summarize findings from functional neuroimaging studies in GAD.
• To focus specifically on task-based blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) studies.

Main Methods:

• Systematic review of task-based fMRI studies investigating GAD.
• Analysis of both a priori hypothesis-driven and data-driven whole-brain findings.

Main Results:

• Abnormal BOLD responsivity in corticolimbic regions (amygdala, anterior cingulate cortex, prefrontal cortex) is consistently observed in GAD.
• Data-driven analyses indicate involvement of the insula and hippocampus, varying with specific tasks.
• Heterogeneity in tasks and sample sizes currently limit generalizability.

Conclusions:

• Convergent evidence suggests altered BOLD responsivity within the corticolimbic circuitry in GAD.
• Functional neuroimaging provides valuable insights into the neural mechanisms of GAD, despite current limitations.